Publication Date:
2014-09-06
Description:
High-entropy alloys are equiatomic, multi-element systems that can crystallize as a single phase, despite containing multiple elements with different crystal structures. A rationale for this is that the configurational entropy contribution to the total free energy in alloys with five or more major elements may stabilize the solid-solution state relative to multiphase microstructures. We examined a five-element high-entropy alloy, CrMnFeCoNi, which forms a single-phase face-centered cubic solid solution, and found it to have exceptional damage tolerance with tensile strengths above 1 GPa and fracture toughness values exceeding 200 MPa.m(1/2). Furthermore, its mechanical properties actually improve at cryogenic temperatures; we attribute this to a transition from planar-slip dislocation activity at room temperature to deformation by mechanical nanotwinning with decreasing temperature, which results in continuous steady strain hardening.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gludovatz, Bernd -- Hohenwarter, Anton -- Catoor, Dhiraj -- Chang, Edwin H -- George, Easo P -- Ritchie, Robert O -- New York, N.Y. -- Science. 2014 Sep 5;345(6201):1153-8. doi: 10.1126/science.1254581.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. ; Department of Materials Physics, Montanuniversitat Leoben and Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben 8700, Austria. ; Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. ; Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. Materials Sciences and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA. georgeep@ornl.gov roritchie@lbl.gov. ; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA. georgeep@ornl.gov roritchie@lbl.gov.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25190791" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
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Medicine
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Natural Sciences in General
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Physics
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